Window assemblies developed and designed particularly for installation in more or less inclined roof surfaces are well known in the art. Among numerous examples disclosed in the art reference could be made e.g. to the roof window assemblies disclosed in U.S. Pat. No. 5,913,785 and published International Patent Applications WO 98/22682, WO 98/22684, WO 98/22685 and WO 98/22686.
In general, such window assemblies include a main frame structure secured to supporting means of the roof structure and a framed window component in connection therewith, either permanently to provide a fixed window or by some kind of pivotal connection to allow turning of the window component with respect to the main frame between a closed position and ventilating positions which may be confined within a specified opening range.
Common main frame structures may be supplied in ready-made form as part of a window assembly in the form of a main frame component to be arranged by so-called deck-mounting against external supporting members of the roof structure around a window opening formed therein.
The main frame structure is frequently made of wood profiles e.g. forming top, side an bottom members of a rectangular frame configuration and covered on externally exposed side faces by flashing members providing weather protection to the wood profiles and securing a tight connection or joint with the roof covering surrounding the window.
Such flashing members are well known in the art and may be supplied in a multitude of different forms, e.g. as a flashing frame made entirely of an elastically deformable material as disclosed in published International Patent Application WO 94/00655.